It makes sense that a balloon filled with a lightweight gas such as helium would float when surrounded by heavier air. But why does filling a huge balloon with hot air also make it float? This ...

Wax is made of carbon and hydrogen atoms bonded together in long chains. The chains are tangled, intertwined, and packed together to make the wax. Water molecules are packed more closely together than ...

What: Earlier this summer we learned about density. Density is the amount of mass in a given volume, or amount of space. Mass is dependent on the number of molecules in an object. Objects that are ...

Imagine you're at a hot air balloon event. The balloonists are busy preparing for flight. They spread out the enormous balloons on the grass and check all the lines. The talk is all about today's ...